I had the same problem about a month ago, and I am assuming that when you say "they arent the best" you are referring to the road and and shtuff that kinda makes them look dirty all the time, right?
Well here is what I did last month and it seriously, seriously looks good. Go to a Pep Boys near you and get some 800 + 1500 grit dry/wet sandpaper, some rubbing compound, and some clear plastic polish (+/- $20 for everything).
~Wet sand the lenses with the 800, then the 1500. You want to do this for a while and use some elbow grease, so you get all of the little knicks out and whatnot
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~Then apply the rubbing compound, and it it pretty easy to do
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~Then polish them and voila! as good as new!
If dirty headlights arent your problem, maybe I can still help, just clarify what it is that you think needs improvement.
